1. Field of the Invention
The present invention relates to a scanning probe microscope with advanced capabilities for sample treatment, and in particular to the improvement of scanning probe microscopes and related apparatuses which, for example, combine scanning probe technology with (stylus) profilometry (for example the DEKTAK 8 ADVANCED DEVELOPMENT PROFILER, model from the VEECO Company) and in this case referred to in the following text as scanning probe microscopes.
2. Background and Relevant Art
A scanning probe microscope comprising a base frame or a base mount to which a probe holder with a probe and a sample mount are attached or can be attached, in which case the probe and sample mount can be moved relative to one another. Information about the surface of a sample which is arranged on the sample mount is obtained by scanning the sample. Scanning probe microscopes such as these are prior art and represent an important key technology in research and development. Many fields of science and industry are profiting from scanning probe microscopy, such as the semiconductor industry, the material sciences, biotechnology and polymer research.
The object of the present invention is to provide a scanning probe microscope as well as a corresponding method, in which the investigation options are also extended and their handling is made considerably easier.
Owing to the high spatial resolution, scanning probe microscopes can be used specifically to investigate very small surfaces. It is normally regarded as being advantageous, in particular in scanning atomic force microscopy (AFM), that no sample preparation, or only a very small amount of sample preparation, is required for the investigation, and the investigations can normally be carried out in ambient conditions. However, specific, repeated and economic influences on samples open up new investigation options in scanning probe microscopy and related apparatuses and methods, allowing the study of influences on sample treatment using data before and after the sample treatment. For example, the destructive spatial imaging method of nanotomography (WO 00/39569) is based on the sequential removal of sample material at a specific point on the sample surface. Unfortunately, however, a number of serious and general technical problems and obstructions exist in the use and in the economical implementation of methods in general which are based on the treatment of a specific sample surface and scanning probe microscopy. If, by way of example, the sample is subjected to a low pressure plasma treatment outside the scanning probe microscope (‘ex situ’), the sample must be repositioned. After installation in the scanning probe microscope, the small sample surface of interest must be found. Various methods and recipes for finding the sample surface of interest (spot) are known in scanning probe microscopy. These generally use so called characteristic landmarks, such as defects in the material or applied scratches, for positioning of the probe and of the sample. However, the known methods are unsuitable for widespread use of these methods since they are time consuming and costly, tedious, uncertain and susceptible to errors, and the problem of finding the same sample spot cannot be solved. This problem impedes widespread economical use and the effective use of methods which are based on the repeated scanning of a specific sample surface.
In situ investigations in the field of scanning probe microscopy in an ultrahigh vacuum (UHV) are known and are prior art (for example P. Geng et al, Rev. Sci. Instrum. 71, 504 508, 2000). These methods and apparatuses are technically complex since they are based on UHV technology. The handling of samples and probes, in particular the process of exchanging samples and probes, is more difficult than with scanning probe microscopes which operate under ambient conditions. In particular, the nature of the sample treatment is restricted and the problem exists that the probe is normally also subject to treatment.